Analysis of Anti-Stealth Characteristics of Terahertz Waves in Plasma Stealth

In this article, the influence of the plasma induced by alpha particles distributed on the surface of aircraft on the reflection characteristics of the incident electromagnetic waves is studied, the spatial distribution of plasma electron density under different atmospheric densities is simulated, the reflectance of the aircraft surface to radar and terahertz waves at different radioactive activity and flight altitude is calculated, and the anti-stealth characteristics of terahertz waves are analyzed. The results show that at the activity of 1 mCi/cm2, the aircraft has relatively small reflectance for both L- and S-band. When the activity is 10 Ci/cm2, the aircraft has a better stealth effect in the frequency range of 10–40 GHz, with reflectance values below 0.04. However, in the terahertz frequency band, when the frequency is greater than 1 THz, the reflectance values are all above 0.99 for both activity values. In addition, by changing the plasma electron density and collision frequency, the aircraft surface can achieve different degrees of stealth shielding effect on radar waves in different frequency bands. The reflectance of the 1–110 GHz band can be reduced by 2.26–60.51 dB maximum, while the reflectance values of the terahertz band are all above −0.6 dB.